WASHINGTON/VIENNA, March 14 (Reuters) - The U.S. government will ask Austria to extradite Ukrainian industrialist Dmytro Firtash to face charges filed in a Chicago court arising from an investigation into international corruption, U.S. prosecutors said on Friday.

One of Ukraine’s most influential oligarchs, Firtash, 48, was arrested in Vienna on Wednesday. On Friday, a court there ordered him held and set bail at $174 million (125 million euros).

“The charges result from an investigation, which the FBI has conducted for several years, of an alleged international corruption conspiracy,” U.S. prosecutors said in a statement.

“Firtash’s arrest is not related to recent events in Ukraine,” they said in a reference to the political crisis between Ukraine and Russia. Documents describing the charges are sealed.

Firtash’s business interests in gas trading and chemicals thrived under ousted Ukrainian President Viktor Yanukovich. He has close links to Russia through his gas concerns.

A final decision on whether to turn Firtash over to the United States was pending, according to a separate statement from the Austrian court.

The court said it would rule on that based on the U.S. extradition request and information from U.S. authorities for which it was waiting.

FIRTASH APPEALS

Firtash was arrested on suspicion of violating laws on bribery and forming a criminal organization in the course of foreign business deals, according to Austrian authorities.

The U.S. Federal Bureau of Investigation has been looking into the case since 2006, Austrian officials have said.

Firtash appealed Friday’s court order, which cited the risk that he might flee, the court said.

He would not be allowed to leave Austria if he posted bail, which was set by taking into account his wealth and the gravity of the suspicions against him, it said.

A court spokesman said Firtash could also appeal the court’s final extradition ruling, and he could take the case to Austria’s justice ministry if an appellate court were to rule against him. He declined to estimate how long the process might last.

Firtash’s company Group DF has said the FBI case appeared to be related to an investment project in 2006, which another group source said was in India.

Group DF said in a statement, ”We know that the actions of the law enforcement organs of Austria in relation to Dmytro Firtash are not linked with the situation in Ukraine, not with the activity of the Group in Europe and America but relate to an investment project in 2006.

“We are sure that the present incident is a misunderstanding and will be resolved very soon.”

Forbes Ukraine magazine last year put Firtash in 14th place on its Ukrainian rich list, setting his fortune at $673 million.

Firtash is not named on an initial European Union list of Ukrainians suspected of misusing state funds and violating human rights. The assets of those on the list are due to be frozen as a result of the crisis over Russia’s incursion into Ukraine’s Crimea.